Goal: The overarching goal of this proposal is to better understand key steps in the utilization and recycling of trehalose in mycobacteria. The disaccharide trehalose is important for multiple aspects of mycobacterial physiology and has been shown to be essential for viability as is the downstream utilization pathway that leads to trehalose monomycolate production and export. Recycling of the trehalose used to build the outer membrane is important for M. tuberculosis virulence and is used to extend a-glucans that have various roles in the bacterium. This research project possesses 2 separate portions related to trehalose metabolism. The first portion of this study aims to develop novel classes of compounds that inhibit the three enzymes of the Antigen 85 Complex. Second, we will use our current knowledge of GlgE protein structure to develop second-generation inhibitors and improved tools for assessing the inhibitor activity of these inhibitors. Since inhibition of GlgE promotes rapid killing of M. tuberculosis, improving upon the current inhibitors will significantly advance our ability to treat TB. It is expected that results obtained from this study will extend the available M. tuberculosis drugs to include compounds that target trehalose biosynthesis and utilization.